This research will examine the effects of societal level changes such as economic development, occupational structure, economic demand, the age structure, and political organization on aggregate retirement rates using cross-national, longitudinal data. Theories of modernization and retirement have argued that high levels of retirement are a response to economic development and modernization. Yet, the theory has failed to precisely specify the causal mechanisms which translate economic development into high retirement levels and has ignored many changes independent of development which may strongly affect retirement. Empirically, tests of the theory have been limited to cross-national studies at one point in time or to time-series studies in one country. The objectives of this research are to construct a causal, theoretical model of aggregate retirement levels which clearly specifies the effects of modernization variables such as economic output, occupational change, and educational levels as well as other important variables such as political structure, job competition, job supply and retirement income. The model will be estimated using cross-national, longitudinal data where it is available and cross-national, synchronic data where it is not. It is our hypothesis that with additional controls, the effects of development on retirement will be much smaller than previously thought. The results should also have implications for the area of cross-national aging and for the importance of macro-sociological forces on the lives of the aged.